Warbler said:
there is only one way to decide for yourself: watch it.
Or you could just travel into the future and ask your future self if the movie's worth seeing. If it isn't, then you can return to the present and refuse to watch it.
Of course, if you never watch it, you won't be able to grow up to become the future version of yourself who warns your past self never to watch in the first place, thus setting off a paradox ...
Oy, but time travel mechanics give me a headache.